Murrayfield has emerged as the front-runner to stage a 'home' British and Irish Lions Test against Japan before next year's tour of South Africa.
The fixture is pencilled in for Saturday, 26 June 2021, with the Lions' tour opener scheduled a week later.
It would be the first Lions home Test since the draw against Argentina in Cardiff in 2005.
Warren Gatland's side face the Stormers in Cape Town on 3 July, with the first Test against the Springboks on 24 July.
However, while Lions and South African Rugby Union sources are both optimistic the tour will be able to proceed as planned, the dates may still be subject to change.
It is understood Lions officials have discussed shifting the tour to later in the year, not only because of the impact of the coronavirus pandemic but also because of the possibility of a new global season which could see the July Test window move to October.
Scotland head coach Gregor Townsend told 5 Live Sport's Guest List he is squarely behind the implementation of a global calendar, and has supported the proposal of running back-to-back international windows in October and November.
"I really hope we do get an aligned calendar," Townsend said.
"My preference is to move to the summer to align with the southern hemisphere and have a really competitive element in the October and November window, as we do with the Six Nations.
"It seems like there is a will from a lot of people to make that happen. It would almost be like a World Cup, but you are flying to the southern hemisphere countries and then coming back to host southern hemisphere teams.
"Having a competitive element - whether it is a cup or league - would add something tangible. It would be great to get the players together for a longer period.
"Just now with the three Test windows - Six Nations, July and November - it has worked OK.
"But from an international perspective to move July into October would be better for continuity and in terms of seeing the players develop, but also it works for the clubs, in that they don't have to have three Test windows in the year.
"Two Test windows means the clubs [also] get a really good long run with their players."
Meanwhile, Murrayfield hosting the pre-tour fixture would be a significant step towards the Lions reconnecting with a potentially disenfranchised Scottish rugby public.
Townsend was part of the last Lions side to win in South Africa in 1997, a team which included fellow Scots Alan Tait and Tom Smith and was coached by Ian McGeechan and Jim Telfer.
But Scottish players have been largely overlooked for the last two tours, with no Scot even featuring in a Test match in New Zealand in 2017, and Townsend hopes it is a different story come 2021.
"It would be great if we had more Scottish representation, that's for sure," he added.
"I think we have the players to perform really well in Tests for the Lions, not just make the touring party."